Chuck



Nov. 1, 1932. A. E. CHURCH CHUCK Filed Jan. 2, 1931 2 Sheets-Sheet l 24 cgwuew roz a? Z. C72 arch,

finer/Ma o- Nov. 1, 1932. A. E. CHURCH 1,835,083

CHUCK Filed Jan. 2, 1951 2 Sheets-Sheet 2 vwc'wtoz v6. 2: C/ZuTc/Z Wane as.

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Patented Nov. 1, 1932 UNITED STATES OF CONNECTICUT PATENT OFFICE ALBERT E. CHURCH, or NEW BRITAIN, GONNECTICUT, Assieivoa TO THE UNION MANUFACTURING COMPANY, OF NEW BRITAIN, CONNECTICUT, -A conroim'rro CHUCK Application filed January 2, 193 1. .Serial No. 506,265.

The invention relates to chucks for metal lathes and the like. Such chucks or other holding devices are provided with jaws to engage and drive the work, and due to the tremendous strain which the chuck bodies must encounter to hold the jaws with a driving grip upon the work, particularly when heavy cuts are being made with the high speed steel of today, said bodies are subject to severe distortion, and moreover, their jaw guides are subject to great wear. It is the object of my invention however, to prov de an improved construction in which dlstortion of the chuck body or head is resisted to the maximum and in which the jaw guides are so formed as to allow easy reconditioning thereof when sufficient wear has occurred to loosen the jaws in said guides.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanylng drawings.

Fig. 1 is a face view of a chuck constructed in accordance with the invention, two jaws being omitted.

Fig. 2 is a fragmentary edge view.

Fig. 3 is a vertical sectional view on line 33 of Fig. 1.

A chuck is shown embodying radially movable jaws 5 which may be slid inwardly and outwardly by means of a slidable wedge 6 constructed and operated in any preferred way. It is to be understood however that the invention is not restricted to chucks operated by wedges, but is adaptable equally well to those embodying any of various jaw-operating means, such as those now commonly used.

The chuck head 7 may be of cylindrical form and is provided with a fiat front face 8, and with radial grooves 9 opening through said front face. In the preferred construction, opposite sides 10 of each groove 9 are strictly parallel and at right angles to the face 8, and the inner side 11 of each groove is flat and at right angles to said sides 10.

Lying against the face 8, is a flat, onepiece strain-resisting plate 12 of heavy form, said plate being preferably of hardened steel to possess maximum strength. This plate is rigidly, yet removably secured against the face 8 by screws or the like 13 and 14, and said plate is provided with radial slots 15 which register with the grooves 9. The slots 15 are of considerably less'width than the grooves 9, so that the portions 16 of the plate 12, along opposite edges of said slots 15,- project inwardly beyond the opposed sides 10 of said grooves, in parallel relation with the inner groove sides 11.

The jaws 5 are provided with relatively wide inner portions 17 which are snugly received in the grooves 9, and said jaws also embody relatively narrow outer portions 18 slidably received in the slots 15. At the uncture of the portions 17 and 18, flat shoulders 19 are provided, said shoulders being in con tact-with the projecting portions 16 of the plate 12. Hence, these plate portions hold the jaws 5 snugly against the inner sides 11 of the grooves 9 and the jaws become sub-1 stantially rigid with respect to the chuck head, although they may of course be radially adjusted.

NVhenever sufficient wear of, the shoulders 19 has taken place to loosen the jaws 5 within their guides, the plate 12 and the jaws may be removed from the chuck head. Then,the face 8 of said chuck head may be faced off an amount equivalent to the wear, the shoulders 19 being also re-dressed if necessary. Then, when plate and jaws are again restored to their proper positions and said plate is again secured in place, the jaws will again be tightly though slidably held against the inner sides'll of the grooves. Hence, by the simple procedure described, the chuck may be so reconditioned as to be as efficient as it was prior to the wear which caused loosening of its jaws.

Another advantage for the structure shown,'is that the heavy hardened plate 12 itself resists wear. Moreover, this plate be ing rigidly secured to the head 7, resists distortion of the latter under the strains which it. encounters during operation of the chuck, providing a structure of indefinite life, instead of one which is necessarily short-lived, as in the past.

To assist the plate 12 in holding the head 7 against radial expansion under strain, said plate and head are provided with co-acting means establishing a peripheral interlock between them. In the present showing, plate 5 12 is provided with .a peripheral rib 20 snugly received in a peripherai groove 21 formed in face 8 of the head 7, said rib and groove prov ding abutting shoulders.

. 0 Preferably, the plate 12 carries a bushing flfr the conventional pilot bar. This bushing may be secured in place by screws or in any other preferred way.

By roviding the novel construction shown and ascribed, a eatly improved chuck is vided' whic distortion under strain is P 'Q reatneted to an extreme minimum and in whi h efiective provision is made for allowing'reconditionmg of the jaw guides when 7 they beoomeworn. As the details disclosed ibe consideredas preferred, they may w; be followed. However, it is to be under SliO d that within the scopeof the invention as claimed,.minor variations may be made. Moreovenwhile the jaws 5 are shown as embodying separate, stepped adjustable, outer '03s 24, it is to be understood that the invention is not restricted-to any jaw details except those requisite to insure roper mountofithe jaws in their gui es.

.olaima- .1. Ina slidable jaw chuck, a head havin radial'grooves through its front face, sai head being provided near the peripheral edge as of said face with a shoulder facing toward the periph of the head, a heavy oneiece 3 plate seen against said face of said nead,

late having an inwardly facing shoultting the aforesaid shoulder and hav- ,o ing radial slots narrower than and registerin; with Said grooves, said plate having sufficient resistance to radial expansion to counteract the weakening effect of said slots andhold said head against radiai expansion 45 strain, and jaws passing slidably through said slots and held in shdable content with walls of said grooves by means of theiportions of said plate along said slots.

2. A structure as specified in claim 1; said 66 late having a'central opening, and a pilot 2 bushing secured in said opening. In whereof I aflix my signature. ALBERT E. CHURCH.

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